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Posted to java-user@axis.apache.org by "I-Sampige, Srinivas" <sr...@boeing.com> on 2003/11/06 21:48:16 UTC

Method overloading

Does SOAP support overloading? If I want to expose two methods-

        1.        sayHello(String firstName)
        2.        sayHello(String firstName, String lastName)	


Then how do I do it in AXIS. Can somebody point me to some samples and materials where I can learn more about this aspect of web services? I haven't been able to find much information about this on the web.

Thanks
Srinivas

Re: Method overloading

Posted by Tom Oinn <tm...@ebi.ac.uk>.

Just to follow up my own post (and apologies!)

 From http://www.w3.org/TR/2002/WD-wsdl12-20020709/

-----
[CLOSED] Issue (issue-operation-overloading):
Should operation overloading be disallowed?
Source: Joyce Yang
WSDL 1.1 allows overloaded operations- operations with the same name but 
different messages. If they are to be disallowed then we must require 
the operation name to be unique within a portType.
Resolution:
Do not allow operation overloading. See minutes for telecon on June 27, 
2002 and follow-on email discussion.
-----

Axis does indeed support overloading of methods, but the services thus 
generated do not expose a WSDL1.2 compliant interface. There are 
workarounds to this; one is to manually split the WSDL into two parts 
that just 'happen' to have the same concrete endpoint, with one version 
of the method in each one. This is a horrible hack but we've used it 
where we need to get the workflow engine to introspect on a service we 
don't control and where the authors have not replied to our email :) The 
better solution for interoperability is to avoid using this feature. Of 
course, if you're only using the autogenerated client stub classes from 
WSDL2Java then you're (probably) not going to see a problem here, just 
bear in mind that anyone who is trying to access your webservice without 
this luxury will almost certainly run into problems.

Cheers,

Tom

Tom Oinn wrote:

> No, this is not allowed as of WSDL1.2 and rightly so, it causes 
> immense confusion with dynamic systems such as workflow engines (our 
> project). Under WSDL1.1 I believe it was allowed but fortunately 
> someone saw sense and removed it.
>
> Cheers,
>
> Tom Oinn
>
> http://taverna.sf.net
>
> I-Sampige, Srinivas wrote:
>
>> Does SOAP support overloading? If I want to expose two methods-
>>
>>        1.        sayHello(String firstName)
>>        2.        sayHello(String firstName, String lastName)   
>>
>>
>> Then how do I do it in AXIS. Can somebody point me to some samples 
>> and materials where I can learn more about this aspect of web 
>> services? I haven't been able to find much information about this on 
>> the web.
>>
>> Thanks
>> Srinivas
>>
>>  
>>
>
>

Re: Method overloading

Posted by Tom Oinn <tm...@ebi.ac.uk>.

Ingrid Falk wrote:
>>>>>>"Tom" == Tom Oinn <tm...@ebi.ac.uk> writes:
>>>>>
> 
>     Tom> Quite correct, and if you are only ever going to use axis and
>     Tom> noone else will ever ever need to access your services then
>     Tom> it's reasonable.  However, in this case you should probably
>     Tom> be using CORBA :)
> Maybe, but i still think AXIS is easier to use than CORBA.

Oh, it is. It's worth bearing in mind though that ease of use from our 
perspective isn't always the main criteria when deciding upon an 
architecture. If any of my students gave that as their sole 
justification for using web services over CORBA I'd probably fail them*, 
there are plenty of other reasons but as always there is no one right 
solution that fits all needs. Good thing too, or many of us would be out 
of a job ;)

Tom

* In this case, 'fail them' translates directly to 'make them buy me 
guinness', it's more productive and less antagonistic :)

Re: Method overloading

Posted by Ingrid Falk <in...@loria.fr>.

>>>>> "Tom" == Tom Oinn <tm...@ebi.ac.uk> writes:

    Tom> Quite correct, and if you are only ever going to use axis and
    Tom> noone else will ever ever need to access your services then
    Tom> it's reasonable.  However, in this case you should probably
    Tom> be using CORBA :)
Maybe, but i still think AXIS is easier to use than CORBA.

Ingrid

Re: Method overloading

Posted by Tom Oinn <tm...@ebi.ac.uk>.

Ingrid Falk wrote:

>     Tom> No, this is not allowed as of WSDL1.2
> -- but still supported by Axis. I have services whith overloaded
> methods that work. This is possible, because as far as I know, AXIS
> doesn't really make use of the wsdl when calling a service method,
> only to generate stubs.
> 
> best,
> 
> Ingrid

Quite correct, and if you are only ever going to use axis and noone else 
will ever ever need to access your services then it's reasonable. 
However, in this case you should probably be using CORBA :)

Tom

Re: Method overloading

Posted by Ingrid Falk <in...@loria.fr>.

>>>>> "Tom" == Tom Oinn <tm...@ebi.ac.uk> writes:

    >> Does SOAP support overloading? If I want to expose two methods-
    >> 
    >> 1.  sayHello(String firstName) 2.  sayHello(String firstName,
    >> String lastName)
    >> 
    >> 
    >> Then how do I do it in AXIS. Can somebody point me to some
    >> samples and materials where I can learn more about this aspect
    >> of web services? I haven't been able to find much information
    >> about this on the web.
    >> 
    >> Thanks Srinivas
    >> 
    >> 
    >> 
    Tom> No, this is not allowed as of WSDL1.2
-- but still supported by Axis. I have services whith overloaded
methods that work. This is possible, because as far as I know, AXIS
doesn't really make use of the wsdl when calling a service method,
only to generate stubs.

best,

Ingrid

Re: Method overloading

Posted by Tom Oinn <tm...@ebi.ac.uk>.

No, this is not allowed as of WSDL1.2 and rightly so, it causes immense 
confusion with dynamic systems such as workflow engines (our project). 
Under WSDL1.1 I believe it was allowed but fortunately someone saw sense 
and removed it.

Cheers,

Tom Oinn

http://taverna.sf.net

I-Sampige, Srinivas wrote:

>Does SOAP support overloading? If I want to expose two methods-
>
>        1.        sayHello(String firstName)
>        2.        sayHello(String firstName, String lastName)	
>
>
>Then how do I do it in AXIS. Can somebody point me to some samples and materials where I can learn more about this aspect of web services? I haven't been able to find much information about this on the web.
>
>Thanks
>Srinivas
>
>  
>